I often run around in the frontier and at seemingly random spots I hear a native american flute play. Often I look around to try to see if there is something around me to look for but I don't see anything. What is this flute-toot for?

You might want to reconsider your approach when in unknown territory. Though the alert song is very useful, you can never know what will happen, and I am certain that you would not want to desynchronize if you are in an important mission.